Timer



Feb. 11, 1958 J. w. A. JACOBSON ET AL 2,822,692

TIMER Filed March 50, 1956 IEi . INVENTOR James WA. Jacobson f?0berf 5. Brooks wifizilm amw mzzwaw' ATTORNEY TIMER James W. A. Jacobson, St. Paul, and Robert B. Brooks,

St. Louis Park, Minin, assignors to the United States of America'as represented by the Secretary of the Army Application March30, 1956, Serial No. 575,281

4 6 Claims. (11. 74-15 The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to us of :any royalty thereon.

This invention relates to ordnance fuze timers, and more especially to escapement mechanisms.

The use of timing mechanisms in ordnance fuzes to produce short time delays is well known, as are the special problems encountered in this field.

This invention concerns a novel means of controlling the speed of a simple untuned verge escapement in an ordnance fuze timer. We accomplish this by attaching an escape wheel and verge to the main verge or, alternately, by limiting the amplitude of oscillation of an inertia wheel driven by the main verge.

An object of this invention is to provide a means, adapted for use in ordnance fuzes, for slowing the speed of an untuned escapement mechanism.

Another object is to provide a means for regulating the speed of an escapement over wide ranges.

A further object of this invention is to achieve the above objects in a simple, cheap device that is easy to manufacture yet rugged and dependable.

Other objects, aspects, uses and advantages of the invention will become apparent from the following description and the accompanying drawings, in which:

Fig. 1 is an exploded view of a first embodiment of this invention.

Fig. 2 is a side view of the first embodiment.

Fig. 3 is a plan of a modification of the first embodiment.

Fig. 4 is an exploded view of a second embodiment.

Fig. 5 is a side view of the second embodiment.

Fig. 6 is a plan of a modification of the second embodiment.

The device shown in Figs. 1 and 2 is an embodiment of a compound escapement. Main shaft 1 is supported by a. frame which includes end plates 12 and 13. The main shaft is turned by some external power source and is retarded by main pawl 4 of main verge 3 acting on a toothed escape wheel 2 which is secured to the shaft 1. The verge 3 is pivoted by shaft 14 which extends between the end plates 12 and 13. The main verge 3 has a slot 5 through which passes main shaft 1. Along the edge of this slot is projection 6 which engages slot 8 of escape wheel or segment 7. This escape segment pivots on shaft 1 and is retarded by verge 10 which is pivoted by shaft 11 to U-shaped bracket 9. Bracket 9 is itself pivoted to shaft 1; however, it may be locked in place by screw 15 in lug 16 attached to end plate 13.

If it is desired that the main shaft 1 rotate relatively rapidly, the screw 15 is withdrawn from engagement with bracket 9. The rotation of shaft 1 and escape wheel 2 causes oscillation of verge 3, bracket 9 and escape segment 7.

If it is desired that the shaft 1 rotate relatively slowly, the screw is brought into engagement with bracket 9. The escape wheel 2 causes verge 3 to oscillate and this A 2,822,692 Patentedrfiebrll, 19 5.8

causes rotation or oscillation of escape segment 7. This rotation or oscillation isretardedby verge 10. The result is that shaft 1.will rotate considerably slower than when screw 15 is notinengagement with bracket 9.

Themodification of Fig. '3 is primarily presented to more clearly illustrate the operation of the first embodiment. It consists-of. an end plate 113 through which passes main shaft 101 to which is attached escape wheel 102. About another shaft 114 is pivoted main verge 103 and bracket 109. Verge 103-has pawls 104 at one endand gear segment; 106. atfthe other. Theteeth of' gear segment 106: mesh with teeth of pinion 108 which is pivoted to' bracket 109.. Connected to the pinion 108 is escape wheel or segment-107. yerge 110 is pivoted to bracketi109 and in contact with'the teeth of the escape segment 107. Latch slides on the end plate 113 to lock bracketl09 in place, The operation is the same as described above in connection with.Figs. 1 and 2.

In the second embodiment shown in Figs. 4 and 5, a main shaft 31 is supported by a frame which includes end plates 42 and 43. Toothed escape wheel 32 is secured to the main shaft 31 and is retarded by pawl 34 of verge 33 which is pivoted by shaft 44 extending between the end plates. Slot 35 in the verge 33 is for the main shaft. Projection 36 from the verge 33 passes through slot 38 in inertia wheel 37. Slot 38 has side walls 38a and 38b spaced from one another. The inertia wheel 37 is pivoted about its center on main shaft 31. The amplitude of oscillation of the inertia wheel 37 is limited by extension 39 abutting stops 40 and 41. These stops are in the form of screws threaded through lugs 45 and 46 on end plate 43.

In operation an external power source causes shaft 31 and escape wheel 32 to rotate. This rotation causes verge 33 to move in one direction, this movement being transmitted to inertia Wheel 37 by projection 36 acting against side wall 38a for instance. When one side of pawl 34 clears one tooth of the escape wheel 32, the force on shaft 31 will tend to reverse the direction of movement of verge 33. However the verge 33 will not immediately reverse because the continuing rotation of inertia wheel 37 causes side wall 38b to move against projection 36. Wheel 37 continues to rotate in its initial direction until projection 39 strikes stop 41. The force of projection 36 on side wall 38b then causes the mechanism to begin the second half of a cycle. Thus the rate at which shaft 31 turns is determined by the amplitude of the inertia wheel oscillation as set by the stops 40 and 41i. e., if the stops are further apart the mechanism will run slower.

The modification of Fig. 6 is presented to more clearly illustrate the operation of the second embodiment. It consists of an end plate 143 to which is journaled escape wheel 132 on main shaft 131. Verge 133 is pivoted to plate 143 and besides pawls 134 has projection 136 in slot 138 of inertia wheel 137. Theinertia wheel is pivoted to the end plate 143. Extension 139 of the inertia wheel limits the amplitude of oscillation of this wheel according to how stops 140 and 141 are adjusted. The operation is the same as the operation of the second embodiment.

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention'as defined in the appended claims.

We claim:

1. An escapement mechanism for ordnance devices comprising; a main shaft; an escape wheel secured to the main shaft; a verge pivoted about an axis parallel to the main shaft with a slot in the verge through which the main shaft passes; a pawl secured to the verge and in contact with teeth of the escape wheel; a second wheel pivoted at its center to the main shaft; 2. projection from the verge extending through a slot in the second wheel; and means cooperating with the second wheel for regulating the speed of its oscillation. p p

2. The invention as defined in claim 1 wherein the means for regulating the speed of oscillation of the second wheel includes an extension on the second wheel and stops mounted for adjustment to a. frame on either side of the extension.

3. The invention as defined in claim 1 wherein the means for regulating the speed of oscillation of the second wheel includes teeth on the second wheel and a pivoted verge in contact with the teeth.

4. The invention as defined in claim 3, the second verge being pivoted to a bracket which is pivoted-about the main shaft, means being provided for locking the bracket in a stationary position.

5. A compound cscapement mechanism comprising: a main shaft with an escape wheel on it; a main verge with a pawl in contact with a tooth of the escape wheel, and said main verge being pivoted about an axis parallel to the main shaft; an escape segment driven by the main verge and said escape segment being pivoted about an 'axis parallel to the main verge axis; and a second verge being spaced from said main verge and in contact with the escape segment, said second verge adapted to regulate the speed of oscillation of said escape segment.

6. A compound escapement mechanism comprising: a main shaft with an escape wheel on it; a main verge with a pawl in contact with a tooth of the escape wheel;

an escape segment driven by the main verge; and a second verge in ,contact with the escape segment, and the second verge being mounted on a bracket; the bracket being mounted for. movement with the main verge; and means for locking the bracket in one position.

References Cited in the file of this patent UNITED STATES PATENTS 2,486;602 V Jensen et al. Nov. 1, 1949 2,503,154 h Graves Apr. 4, 1950 2,570,170 Viti Oct. 2, 1951 2,674,890 Mosset Apr. 13, 1954 

